1. Field of the Invention
The present invention relates generally to ink-jet technology and, more particularly, to methods and apparatus for producing hard copy with modular ink-jet hard copy devices and systems.
2. Description of Related Art
The art of ink-jet technology is relatively well developed. Commercial products such as computer printers, graphics plotters, copiers, and facsimile machines employ ink-jet technology for producing hard copy. The basics of this technology are disclosed, for example, in various articles in the Hewlett-Packard Journal, Vol. 36, No. 5 (May 1985), Vol. 39, No. 4 (August 1988), Vol. 39, No. 5 (October 1988), Vol. 43, No. 4 (August 1992), Vol. 43, No. 6 (December 1992) and Vol. 45, No.1 (February 1994) editions. Ink-jet devices are also described by W. J. Lloyd and H. T. Taub in Output Hardcopy [sic] Devices, chapter 13 (Ed. R. C. Durbeck and S. Sherr, Academic Press, San Diego, 1988).
Fundamentally, FIG. 1 (PRIOR ART) depicts an ink-jet hard copy apparatus, in this exemplary embodiment a computer peripheral printer, 101. A housing 103 encloses the electrical and mechanical operating mechanisms of the printer 101. Generally, operation is directed by an electronic controller (usually a microprocessor or application specific integrated circuit (xe2x80x9cASICxe2x80x9d) controlled printed circuit board, not shown) connected by appropriate cabling to a computer (not shown). It is well known to program and execute imaging, printing, print media handling, control functions and data processing logic with firmware or software instructions. Cut-sheet print media 105, loaded by the end-user onto an input tray 107, is fed by a suitable internal paper-path transport mechanism (not shown) to a printing station where graphical or photographical images and alphanumeric text is created. A carriage 109, mounted on a slider rod 111, scans the print medium. An encoder strip 113 is provided for keeping track of the position of the carriage 109 at any given time. A set 115 of individual ink-jet pens, or print cartridges, 117A-117D is releasably mounted into the carriage 109 for easy access (generally, in a full color system, inks for the subtractive primary colors, cyan, yellow, magenta (CMY) and true black (K) are provided). Once a printed page is completed, the print medium is ejected by the transport mechanism onto an output tray 119.
At the heart of an ink-jet hard copy apparatus is the writing instrument itself, commonly called a xe2x80x9cprint cartridgexe2x80x9d or a xe2x80x9cpen.xe2x80x9d As shown in FIG. 2 (the subject of separate patent applications assigned to the assignee of the present invention), an exemplary ink-jet pen 210 includes a body, or shell, 212 that encases an ink reservoir, or an ink accumulator chamber and related print head pressure regulator mechanisms (not shown), containing either fluid ink or hot melt type printing fluid. A print head 214 includes a nozzle plate 216 having a plurality of small (e.g., diameter approximately twenty xcexcm) orifices 217 from which tiny droplets of ink (e.g., approximately ten picoliters) are ejected onto adjacent print media as the pen(s) scan across a printing zone at a high speed (approximately 25 inches per second, xe2x80x9cipsxe2x80x9d), depositing ink droplets in patterns that through dot matrix manipulation form alphanumeric text characters or graphic images. A flex circuit 218 includes electrical contacts 220 for connecting the pen 210 to the electronic controller. The print head elements have a limited life due to electrical, thermodynamic, and fluid dynamic loads imposed during operation. Thus, in the current state of the art, a costly and functionally significant portion of the writing system must be replaced with each print cartridge change.
The apparatus elements directly involved with inking a print mediaxe2x80x94in other words, all components of the system which come into contact with ink other than the print media itselfxe2x80x94are referred to hereinafter as a writing engine; non-writing elements of the hard copy apparatus system are referred to hereinafter as a hard copy engine. Cartridges, pens, ink-reservoirs, and the like are referred to as ink-jet consumables. (Use of these terms is for convenience of description and is not intended as any limitation to the scope of the invention, nor should any such intention or limitation be implied therefrom.)
Having become commercially practicable in the early 1980""s, ink-jet technology is a relatively young field of invention. In state-of-the-art thermal ink-jet systems, two complementary writing instruments have become commercially viable. The first is the disposable print cartridge type; the second is the semipermanent print head pen type.
The disposable writing instrument has a self-contained reservoir (xe2x80x9con-axisxe2x80x9d or xe2x80x9con-board;xe2x80x9d generally meaning on the pen carriage subsystem) for storing ink and providing appropriate amounts of ink to the print head during a printing or servicing cycle throughout the life of the writing instrument. When out of ink, the entire print cartridge is replaced by the end-user.
When ink-jet technology was in its early stages, print head life expectancy was more or less equivalent to the amount of ink that was held in the on-board ink reservoir. More recently, advances in the state-of-the-art for print head design and manufacture has led to a longer operational life expectancy for the print head than can be used with a reasonably-sized, non-replaceable ink reservoir. Thus, the development and commercialization of a second commercial type using a replaceable ink writing subsystem that employs a semi-permanent printing element, where the ink is supplied to the print head mechanism from a replaceable ink reservoir located either on-axis or xe2x80x9coff-axis,xe2x80x9d (with respect to the pen carriage subsystem), such as a biased ink bladder or bag (see e.g., U.S. Pat. No. 5,359,353 (Hunt et al.) assigned to the common assignee of the present invention and incorporated herein by reference). This second type of writing instrument, the semipermanent pen, can also include mechanisms for regulating both requisite print head back pressure (in a free-ink ink-jet writing instrument) and the flow of ink from the off-board ink reservoir to the pen (shown in FIG. 2 as having an ink inlet mechanism 222 that would be coupled 223 to the replaceable or refillable off-axis ink supplies 224). In the off-axis type of hard copy apparatus, separate, replaceable or refillable, ink reservoirs are located within the fixed apparatus housing 103, FIG. 1, and appropriately coupled to the moving pen set 115 via ink conduits, such as tubes that are impervious to the ink chemicals. In the on-axis type of hard copy apparatus, separate, replaceable or refillable, ink reservoirs couple to the print head ink interface directly and are located on the moving pen carriage system.
Each commercial configuration has advantages and disadvantages. The disposable print cartridge type writing instrument is simple and easy to use but costly, as the relatively expensive print head mechanism is discarded along with the on-axis ink chamber once the ink is fully consumed. Moreover, the non-replaceable on-axis ink chamber in and of itself inherently limits the number of pages which can be printed due to its relatively small ink capacity. With the increase in print head longevity, end users have turned to refill kits or lower cost re-manufactured print cartridges that are less expensive than replacement with a new print cartridge. The use of ink refill kits is often a messy task. Still further, the need and desire for even less expensive ink continues to grow. The recent commercialization of near photographic quality ink-jet printing has increased the end user""s consumption of ink much faster than in the past when simple text and color graphics imagery was the norm. Even traditional business documents are now including more images and complex graphics, thus consuming more ink. Naturally, end user replacement costs increase.
The semipermanent pen type system is potentially more economical to the end-user. The on-axis, replaceable, ink subsystem offers lower cost per page printing, but the end user is required to replace smaller ink reservoirs more often than with off-axis implementations. This is due to the physical limitation of how much ink can be reasonably carried on the carriage system. Similar to the disposable print cartridge system, there are also throughput and size penalties due to the mass and volume of the on-axis ink reservoirs. The off-axis ink reservoir type hard copy apparatus potentially can have a smaller carriage and offer larger ink reservoir, the penalty is a more complex design, including additional intra-apparatus ink delivery mechanisms which add cost. The benefits of the larger ink reservoir are in potentially higher throughput due to a lower mass carriage, lower user intervention rates, and even lower cost per page. In a full color hard copy system using a plurality of semipermanent pens, a plurality of off-axis ink reservoirs, and a concomitant set of interconnects, if a printing error occurs, the source of the problem can be difficult to locate. End-user diagnosis may be impossible unless the manufacturer provides expensive troubleshooting technology. Changes in ink formulationxe2x80x94either by the original equipment manufacturer or by a second source using cheaper materials and chemicalsxe2x80x94can result in an end-user inadvertently replacing a reservoir with an incompatible model, again resulting in printing errors or even catastrophic equipment failures. Still further, in some implementations certain elements of the writing subsystem are not replaced with the ink supply, such as reservoir-to-pen tubing, valves, and the like; thus, design criteriaxe2x80x94including ink chemical formulationsxe2x80x94must be employed so that these elements have a life expectancy as great as that of the hard copy engine components.
Moreover, all of the above configurations require a costly, permanent (i.e., matching the hard copy system life expectancy), service station which includes the primary functions of wiping print head nozzle orifices of pooled ink (wiper(s)), collecting waste ink (spittoon(s)), and providing print head protection by capping during non-use (caps or capping devices). While seemingly a simple device, ink-jet service station technology presents many design challenges. Non-replaceable servicing elements must be designed to last the lifetime of the hard copy engine. For example, design constraints are placed on both product size and printing element servicing algorithms due to the limited capacity of a permanent spittoon. The spittoon must be large enough to hold ink residue from all of the servicing operations over the lifetime of the hard copy engine, not just the writing engine. This limits the volume of ink which can be spit during each service interval. Limiting the amount of ink for print head servicing limits the design flexibility for writing instruments. Furthermore, extended usage can cause some of the servicing elements, namely the cap and wiper to fatigue and wear out, or the spittoon to cake and become a problem. Note also, that print head failures, such as leaking ink, can make the servicing elements inoperable; failed servicing components can cause failures in any new writing instrument subsequently installed. Moreover, if a new print cartridge contains an ink that is incompatible with ink which has been left on the servicing elements from a previous print cartridge, the new print cartridge may fail due to ink contamination from the service station. By not replacing the servicing elements with each new print cartridge, the choice of future inks is limited by the composition of past ink usage. Thus, permanent service stations raise manufacturing and support costs.
One key to the commercial success of both disposable print cartridge and semipermanent pen ink-jet printing systems is the high print qualityxe2x80x94approaching photographic, electrophotographic, and laser printing qualityxe2x80x94at a relatively low cost achieved through the use of replaceable printing elements. While it is commercially known to package and sell ink-jet components together, the present invention provides a concept using a new approach to both the ink-jet consumables and the hard copy apparatus. The goal is to obtain the benefits of both disposable and off-axis ink-jet technologies without the associated disadvantages of each. As such, re-partitioning of state-of-the-art ink-jet printing components and functions within an ink-jet hard copy apparatus is undertaken.
In its basic aspects, the present invention provides a method of manufacturing an ink-jet hard copy apparatus. The method includes the steps of:
fabricating an ink-jet hard copy engine having no ink-jet wet components; and
fabricating a plurality of unitary, swappable, ink-jet writing engines containing all ink-jet wet components, equipping the hard copy engine and the writing engine for replaceably interfacing writing engines with the hard copy engine such that the hard copy engine is reusable with a sequential plurality of writing engines.
In another basic aspect, the present invention provides a method of assembling an ink-jet hard copy apparatus having an ink-jet hard copy engine including known manner ink-jet printer paper transport devices. The method includes the steps of:
supplying at least one, unitary, ink-jet module having all wet components of an ink-jet hard copy apparatus, including at least one ink-jet print head, contained therein in an operative configuration; and
inserting the module into the ink-jet hard copy engine such that insertion of the module automatically integrates the wet components with respect to the paper transport devices in an operationally functional and print head aligned configuration.
In another basic aspect, the present invention provides a method for improving operating characteristics of an ink-jet hard copy apparatus. The method includes the steps of:
providing point of use selectively replaceable, unitary construction, first writing engine modules containing all ink-jet apparatus wet components of a first technology set for said hard copy apparatus;
providing point of use selectively replaceable, unitary construction, second writing engine modules physically compatible with said first writing engines and containing all ink-jet apparatus wet components wherein at least one ink-jet apparatus wet component is of a second technology set superceding said first technology set; and
replacing a first writing engine module with a second writing engine module in said hard copy apparatus. Steps of providing the second writing modules with wet component technological upgrades over the wet components of first writing engine modules, and providing the second writing modules with up-loadable code for transfer to said hard copy apparatus are considered.
In another basic aspect, the present invention provides a method of converting an ink-jet hard copy apparatus from having a first ink-jet printing characteristic set to having a different, second ink-jet printing characteristic set. The method includes the steps of:
providing a plurality of classes of ink-jet writing engines, each class having a different ink-jet printing characteristic set;
providing a hard copy engine having at least one bay for selectively receiving ink-jet writing engines therein such that insertion of a writing engine automatically configures the ink-jet hard copy apparatus;
inserting a writing engine of a first class in said bay; and
converting the hard copy apparatus to a different ink-jet printing characteristic set by removing the writing engine of a first class and inserting a writing engine of a second class.
Yet another basic aspect, the present invention provides a method of restoring an ink-jet hard copy apparatus printing functionality. The method includes the steps of:
providing an ink-jet hard copy engine device having all dry components of an ink-jet printer including at least one cassette-type bay;
providing point of use selectively replaceable, unitary, ink-jet writing engines having all wet components of an ink-jet printer in a cassette adapted for insertion into said cassette-type bay; and
restoring printing functionality of the hard copy apparatus by replacing a non-functioning writing engine with a functioning writing engine.
In another basic aspect, the present invention provides another method for restoring an ink-jet hard copy apparatus printing functionality. The method includes the steps of:
providing an ink-jet hard copy engine device having all dry components of an ink-jet printer including at least one cassette-type bay;
providing point of use selectively replaceable unitary ink-jet writing engines having all wet components of an ink-jet printer in a cassette adapted for insertion into said cassette-type bay, each of said writing engines constructed for point of use replacement of individual wet components therein; and
restoring printing functionality of the hard copy apparatus by either replacing individual wet components of a non-functioning writing engine or by replacing a non-functioning writing engine with a functioning writing engine.
In another basic aspect, the present invention provides a method of reconfiguring hard copy apparatus. The method includes the steps of:
providing an installed base of hard copy apparatus, each having a hard copy engine adapted for sequentially receiving end-user swappable modules including all ink-jet wet subcomponents in a unitary, self-contained, ink-jet writing engine; and
providing end-users with a selection of said modules having a variety of ink-jet printing characteristics such that selection and swapping of modules reconfigures the apparatus to the printing characteristics associated with a selected module.
Among further basic aspects, the present invention provides a modular ink-jet apparatus having a writing engine in which all of the individual elements involved directly with the inking process are combined into one easily storable, disposable, or refurbishable, and swappable module. A compatible hard copy engine is also provided.
In a basic aspect, the present invention provides a hard copy apparatus, having writing engine modules for inking print media, each module including ink-jet printing mechanisms for transferring ink from the writing engine modules to print media, servicing mechanisms for maintaining ink-jet functional integrity of the writing engine module, at least one predetermined ink, at least one ink containing mechanisms for containing a predetermined quantity of the at least one predetermined ink, delivering mechanisms for delivering the ink from the containing mechanisms to the ink-jet printing mechanisms, electrical mechanisms for connecting power and control to the writing engine mechanisms, and housing mechanisms for housing the printing mechanisms, servicing mechanisms, ink, ink containing mechanisms, delivering mechanisms, and electrical mechanisms, in a respective operational configuration as a selectively replaceable unit within the hard copy apparatus; and, hard copy engine mechanisms for delivering print media to and from a printing zone location of a hard copy engine printing station and for locating the writing engine relative to the printing zone location.
In another basic aspect, the present invention provides a writing engine for use with a hard copy apparatus adapted for selectively receiving a writing engine therein, including: ink-jet printing mechanisms for transferring ink to print media; at least one predetermined ink; at least one ink containing mechanisms for containing a predetermined quantity of the at least one predetermined ink; delivering mechanisms for delivering the ink from the containing mechanisms to the printing mechanisms; electrical mechanisms for connecting power and logic signals to the writing engine; servicing mechanisms for servicing the ink-jet printing mechanisms; housing mechanisms for housing the printing mechanisms, ink, ink containing mechanisms, delivering mechanisms, electrical mechanisms, and servicing mechanisms in a unified mounting containment providing a replaceable modular unit; and the housing mechanisms and the ink-jet printing mechanisms having mechanisms for selectively interfacing with the hard copy apparatus when received therein such that the ink-jet printing mechanisms is positioned for printing ink onto the print media.
In another basic aspect, the present invention provides writing module subsystems for an ink-jet hard copy apparatus adapted for receiving at least one writing module subsystem in an operational configuration with the ink-jet hard copy apparatus, each of the writing module subsystems including: all components of the ink-jet hard copy apparatus which come into contact with ink, and mechanisms for selectively coupling and decoupling a writing module subsystem as a unit to and from the hard copy apparatus, respectively, such that writing module subsystems are selectively swappable. The components included mechanisms for protecting fluidic integrity of printhead components when the writing module subsystem is decoupled from the hard copy apparatus.
In another basic aspect, the present invention provides a writing module subsystem for an ink-jet hard copy apparatus adapted for receiving the writing module subsystem in an operational configuration therewith, including: all wet components of the ink-jet hard copy apparatus; mechanisms for electrically connecting the writing module subsystem to the ink-jet hard copy apparatus; mechanisms for mechanically aligning the writing module subsystem to the ink-jet hard copy apparatus; and mechanisms for selectively off-loading the writing module subsystem as a unit from the hard copy apparatus and maintaining functional integrity of the wet components while the writing module subsystem is off-loaded such that a writing module subsystem is reusable by reinserting the writing module subsystem into the ink-jet hard copy apparatus.
In yet another basic aspect, the present invention provides an ink-jet writing engine including a unitary module containing all wet components for an ink-jet hard copy apparatus mounted respectively in an operational construct, having an electrical interface and a mechanical interface for integrating the module into a hard copy apparatus such that there is no fluidic interface between the module and the hard copy apparatus other than the transfer of printing fluid from the module onto print media within the hard copy apparatus.
In yet another basic aspect, the present invention provides an ink-jet writing engine including: a housing; an ink reservoir within the housing; ink contained within the reservoir; a writing instrument within the housing; fluidic coupling between the ink reservoir and the writing instrument; a service station within the housing mounted in operational relationship for servicing the writing instrument; and electronic controls mounted within the housing connected to at least the writing instrument and containing control information specific to the writing engine printing and servicing functionality.
In still another basic aspect, the present invention provides a hard copy engine for a hard copy apparatus adapted for using a cassette-type writing engine containing all wet components of an ink-jet system, including at least one ink reservoir having ink therein fluidically coupled to an inking mechanisms within the writing engine for transferring ink from the writing engine to print media within the hard copy apparatus using ink-jetting processes. The hard copy engine includes: a printing station; mechanisms for transporting print media to and from the printing station; and mechanisms for interfacing the hard copy engine mechanically and electrically with the writing engine, the mechanisms for interfacing including a cassette bay for receiving the writing engine therein for positioning the writing engine relative to the hard copy apparatus, mechanisms for mechanically and electrically engaging and activating the writing engine wet components, and mechanisms for aligning the inking mechanisms of the writing engine to the printing station.
In another basic aspect, the present invention provides a hard copy engine including: an ink-jet printing station; a print media transport mounted relative to the printing station to move print media to and from the printing station; a writing engine mount having a writing instrument interface for aligning writing engine ink-jet writing instruments to the printing station such that writing engines are interchangeable, and an ink-jet service station activator mounted relative to the writing engine mount such that the activator interfaces with a writing engine service station, wherein the hard copy engine has no components that contact ink.
In another basic aspect, the present invention provides a modular hard copy apparatus including: a first unitary module including all hard copy engine components, the first unitary module having a first equipment life expectancy; a second unitary module including all ink-jet writing engine components, the second unitary module having a second equipment life expectancy substantially shorter than the first equipment life expectancy; and located on the first unitary module and the second unitary module, complementary mechanisms for selectively interfacing the second unitary module into the first unitary module such that inserting the second unitary module into the first unitary module automatically forms an operationally ready ink-jet hard copy apparatus wherein the second unitary module is replaceable. Furthermore, the second unitary module is replaceable a plurality of times wherein the number of replacement times is approximately equal to the ratio of the first equipment life expectancy to the second equipment life expectancy.
In another basic aspect, the present invention provides an ink-jet hard copy apparatus including: an integrated first module including all hard copy engine dry components, the integrated first module having a first equipment life expectancy; an integrated second module including all ink-jet writing engine wet components, the integrated second module having a second equipment life expectancy substantially shorter than the first equipment life expectancy; and located on the integrated first module and the integrated second module, complementary mechanical and electromechanical mechanisms for selectively interfacing the integrated second module into the integrated first module such that inserting the integrated second module into the integrated first module automatically forms an operationally ready ink-jet hard copy apparatus wherein the integrated second module is replaceable throughout the first equipment life expectancy.
In a further basic aspect, the present invention provides a method for operating a hard copy apparatus, including capturing an insertable writing engine containing all ink-jet wet components into a compatible hard copy engine such that ink-jet printing functions and ink-jet component servicing functions are automatically integrated into the hard copy apparatus by inserting the writing engine therein.
In another basic aspect, the present invention provides an apparatus for producing hard copy including: an ink-jet writing engine, having a printing element; and an ink-jet hard copy engine, having a receiving station wherein the writing engine and the hard copy engine are selectively interlocked such that the hard copy engine seizes the printing element and further such that the hard copy engine can selectively remove the printing element from the writing engine and transport the printing element to a position for ink-jet printing and selectively return the printing element to the writing engine when not inkiet printing.
In another basic aspect, the present invention provides an improved ink-jet hard copy system including the combination of a plurality of interchangeable writing engines in the form of cassette modules, each cassette module containing all wet components of an ink-jet hard copy system, the plurality providing differing ink-jet printing capabilities; and at least one hard copy engine, containing no wet components of an ink-jet hard copy system, for selectively receiving at least one cassette module therein for forming an operational ink-jet hard copy system together therewith.
In another basic aspect, the present invention provides an ink-jet system, the system including (1) a writing engine cassette, including: a printing component having an inlet for receiving at least one ink therethrough, a print head, and a manifold component for transferring ink from the inlet to the print head, at least one ink reservoir component fluidically coupled to the printing element; at least one formulation of ink contained within the reservoir; a servicing component for capping and wiping the print head and for receiving waste ink spit by the print head during servicing thereof; a first electronic controller component connected to the print head; a first electrical connector component for connecting power and control signals to the cassette; electrical wiring connecting the first electronic controller to the first electrical connector; a housing containing all components of the cassette; and (2) a hard copy engine, including: a cassette bay for receiving the writing engine cassette therein; a carriage for receiving the printing component when the cassette is received in the cassette bay and for translationally moving the printing component out of and back into the writing engine cassette; a reversing motor coupled to the carriage for providing translational motion thereto; a mechanism for feeding print media to a position proximate to the printing component when the carriage is translationally moving the print component; a second electrical connector component for connecting to the first electrical connector component when the cassette is received into the cassette bay; a second electronic controller for providing power and control signals; electrical wiring connecting the second electrical connector to the second electronic controller; a mechanism for coupling to and activating functions of the servicing component when the cassette is received in the cassette bay; and a housing encompassing the hard copy engine.
In another basic aspect, the present invention provides a hard copy apparatus including: a hard copy engine, having a print media transport subsystem for moving print media through a print zone region of the hard copy engine and a cassette bay for receiving writing engines therein; and a plurality of writing engines for being selectively inserted into the cassette bay and removed from the cassette bay such that insertion into the cassette bay aligns the writing engine to the print zone region, each of the writing engines containing essentially all wet components of an ink-jet hard copy apparatus and wherein each of the writing engines has differing printing characteristics.
In another basic aspect, the present invention provides an ink-jet printing system including: a hard copy engine having a cassette bay; a first writing engine cassette including ink having a first composition; and a second writing engine cassette including ink having a second composition, wherein the first composition and the second composition have mutually incompatibilities for ink-jet printing, the cassette bay selectively receiving either the first writing engine cassette or the second writing engine cassette for printing such that no contamination of the hard copy engine is incurred due to the mutual incompatibilities during serial selection of the first writing engine and the second writing engine.
It is an advantage of the present invention that modular writing subsystems and modular hard copy engine subsystems can be independently developed as improvements to the state of the art progress.
It is an advantage of the present invention that it provides an OEM with the capability of repeatedly converting an installed base of hard copy engines to improved writing engine technologies.
It is an advantage of the present invention that it permits designs which match ink reservoir volumes to print head life expectancy, optimizing component matching for both performance and cost.
It is an advantage of the present invention that it provides a modular approach to ink-jet writing systems that is convenient and economical for end-users and original equipment manufacturers (xe2x80x9cOEMxe2x80x9d) alike.
It is an advantage of the present invention that its modular replacement features virtually eliminate the need for ink-jet writing system troubleshooting procedures.
It is an advantage of the present invention that it improves the manufacturability of ink-jet hard copy engine apparatus by eliminating assembly operation xe2x80x9cwetxe2x80x9d processes, i.e., those dealing with bulk supplies of ink, tubes filled with ink, and the like.
It is another advantage of the present invention that it uses the fewest number of replaceable individual components, if any, and fewest number of interfaces between the writing engine and the hard copy engine, thereby reducing cost and complexity of operation and use
It is another advantage of the present invention that full replaceability of the writing engine in a single module provides more degrees of freedom to design modifications in accordance with the advancement of the state of the art and to solve writing engine problems in an installed base.
It is another advantage of the present invention that it permits the OEM to introduce upgrades at very low cost, if any at all, to the end user.
It is another advantage of the present invention that limited-life service station components can be manufactured to specifications for the estimated life of the writing engine module rather than that of the hard copy engine, thereby lowering manufacturing cost.
Because writing system failures can be caused by both too little or too much usage, it is an advantage of the present invention that it provides a writing engine that can have an estimated life expectancy based on either time or usage, e.g., 1-year or a set number of printed pages, whichever occurs first.
It is a further advantage of the present invention that it is adaptable to a variety of repeatedly changing implementations based on type of use: home, office, recreational hobby, child computer use activities, and the like.
It is a further advantage of the present invention that it is adaptable to providing the end user with a variety of selectively swappable modules targeted to producing different hard copy results, e.g., continuous black text, color graphics, grey scale imaging, full color photographic quality printing, and the like, based upon the user""s immediate need.
It is a further advantage of the present invention that it is adaptable to providing the end user with a variety of cost options, e.g., slower/lower cost modules versus faster/higher cost modules; low quality/low cost modules versus photographic quality/high cost modules.
It is still a further advantage of the present invention that it provides the OEM with a simpler recycling contingencies.
It is still another advantage of the present invention that it provides the OEM with refurbishing and re-marketing capability.
It is still another advantage of the present invention that it provides a more environmentally conscious product.
It is still another advantage of the present invention that it provides the OEM and end user with simpler, plug-and-play, product testing procedures.
It is still another advantage of the present invention that a unitary modular writing engine provides the OEM a higher shipped-product reliability factor.
It is yet another advantage of the present invention that it reduces the printing cost per page.
It is yet another advantage of the present invention that it allows an ink-jet hard copy apparatus with a smaller workspace footprint.
It is yet another advantage of the present invention that it allows more variety of writing systems for specialty needs.
It is a further advantage of the present invention that it allows separate hard copy engine and writing engine product development strategies.
It is a further advantage of the present invention that it allows simplified commercial distribution supply chain management.
It is a further advantage of the present invention that it permits separate sourcing of hard copy engines which does not require intimate knowledge of inks jet technology.
It is yet a further advantage of the present invention that it permits repeated removal and storage of an ink-jet writing subsystem without the need for special mechanisms to prevent degradation prior to reuse.
Other objects, features and advantages of the present invention will become apparent upon consideration of the following explanation and the accompanying drawings, in which like reference designations represent like features throughout the drawings.